Book excerpt: From the 100-part Penguin Great Ideas series comes a rumination on relationships, courtesy of one of the most influential French Renaissance philosophers. Michel de Montaigne was the originator of the modern essay form; in these diverse pieces he expresses his views on friendship, contemplates the idea that man is no different from any animal, argues that all cultures should be respected, and attempts, by an exploration of himself, to understand the nature of humanity. Penguin Great Ideas: Throughout history, some books have changed the world. They have transformed the way we see ourselves—and each other. They have inspired debate, dissent, war, and revolution. They have enlightened, outraged, provoked, and comforted. They have enriched lives—and destroyed them. Now Penguin Great Ideas brings you the works of the great thinkers, pioneers, radicals, and visionaries whose ideas shook civilization and helped make us who we are. Other titles in the series include Niccolò Machiavelli's The Prince, Thomas Paine's Common Sense, and Charles Darwin's On Natural Selection.